This invention relates generally to computer systems which utilize devices on printed circuit cards which may be added to or removed from the system the system is initialized and while the system is powered up.
Complex electronic equipment is typically constructed as a set of printed circuit cards which connect to a backplane or motherboard (hereinafter together referred to as a backplane), wherein each printed circuit card contains a section or module of the equipment and the backplane contains the interconnections between the circuit cards. This construction allows cards to be physically removed and inserted into connectors or expansion xe2x80x9cslotsxe2x80x9d which are, in turn, connected to the backplane or motherboard. The connectors allow a card and the associated peripheral to be easily added or removed from the computer system, thereby allowing for maintenance and system configuration, changes.
In many electronic systems, the printed circuit cards must be inserted or removed from their connectors in order to configure the system before the system is powered up or initialized. However, more recently, electronic systems have been designed so that some or all of the printed circuit boards can be inserted or removed from their connectors while the associated electronic system is powered up and continues to operate, a capability called xe2x80x9chot swappingxe2x80x9d or xe2x80x9chot pluggable.xe2x80x9d
Some standards that include hot swapping capability have been developed. For example, computers and peripheral devices which adhere to the Personal Computer Memory Card International Association (PCMCIA) standard permit the hot insertion and hot removal of peripherals and this standard is presently in common use with notebook and laptop computers. Consequently, many peripheral devices that adhere to the PCMCIA standard are already in existence.
Aside from obvious power surge problems that occur when a card is inserted into the system, one impediment to inserting or removing peripheral devices from some electronic systems while they continue to operate arises from operator error. For example, when the card is being inserted, the operator may inadvertently touch the card against another adjacent card or against exposed connections in the backplane or motherboard. The result is that an electrical short circuit is created which can apply power to inappropriate places in the inserted card or the existing cards and damage them. Since there is no way to predict how the shorts will occur, they cannot be eliminated by design.
Consequently, although hot pluggable cards are designed to be inserted and removed from. an operational system, in some cases their use is curtailed to prevent the possibility of a catastrophic failure. Accordingly, there is a need to prevent such a possibility.
In accordance with the principles of the invention, an insulating guard is mounted over the backplane or motherboard. The insulating guard has openings that expose a only the connectors and allow a hot pluggable circuit card to be inserted without the possibility of shorting the backplane. In order to prevent contact between a card being inserted and adjacent cards that have already been connected to the system, the invention provides for insulating card dividers that are connected to the insulating guard and fit between adjacent cards. In accordance with one embodiment, the card dividers are attached to the insulating guard by parts that snap together. In accordance with another embodiment, the card dividers are attached to the insulating guard by fasteners. In accordance with still another embodiment, the card dividers are attached to the insulating guard by adhesives.